In his 2009 book, Anil Aggrawal compiled a list of 547 terms describing paraphilic sexual interests. He cautioned, however, that "not all these paraphilias have necessarily been seen in clinical setups. This may not be because they do not exist, but because they are so innocuous they are never brought to the notice of clinicians or dismissed by them. Like allergies, sexual arousal may occur from anything under the sun, including the sun."